Punch shifting apparatus for heading machines



PUNCH SHIFTING APPARATUS FOR HEADING MACHINES L A n M A Y B B E 4 Sheets-Sheet Filed June 23, 1966 ORNEYS INVENTORS Evuum B. Bum/n Joseph Pmzwro 101L550 w M Oct. 7, 1969 E. B. BYAM ETAL 3,470,727

PUNCH SHIFTING APPARATUS FOR HEADING MACHINES Filed June 23, 1966 4 Sheets-Shea t 3 INVENTORS Erwm B. Bqam Joseph Pmzufio ATTURNIz'YS Uct. 7, 1969 E. B. BYAM ET AL 3,47%?

PUNCH SHIFTING APPARATUS FOR READING MACHINES Filed June 23, 1966 4 Sheets-Sheet 1 INVENTYDRS Evwm B. Bupm (Yo se Ph Pmzu+o Def/o OMQ ATTORNEYS United States Patent Ofifice 3,470,727 Patented Oct. 7, 1969 3,470,727 PUNCH SHIFTING APPARATUS FOR HEADING MACHINES Erwin B. Byam and Joseph Pizzuto, Wolcott, Conn., as-

signors to Textron, Inc., Providence, R.I., a corporation of Rhode Island Filed June 23, 1966, Ser. No. 559,800 Int. Cl. B21j 7/16; B23g 9/00; B21k 1/44 U.S. Cl. 72-403 11 Claims ABSTRACT OF THE DISCLOSURE A heading machine which comprises a gate and a die, wherein the gate is reciprocably movable toward and away from the die. Pivotally and separately mounted on the gate are first and second punch carriers wherein each of the punch carriers pivots between a first and second position so as to alternatively align the punches on the punch carriers with the die. Also pivotally carried on the gate is a member which is pivoted between first and second positions and first and second two-bar toggle linkage means connect the member with said first and second punch carriers. Drive means pivot said member so as to simultaneously pivot said punch carriers in timed relation with the gate to sequentially position and align said punch carriers and the punches thereon with the die.

This invention relates to heading machines and more particularly relates to two-blow heading machines using shifting punches.

Known heading machines using shifting punches on a moving gate have heretofore had such punches held in an operative position after shifting by wedges or stop screws. However, as the requirements for increased speeds of operation of heading machines are made these known punch-shifting and locking mechanisms have been found to be impractical for use because of the higher accelerations involved in the higher speed machines.

In a two-blow header or heading machine a piece of rod stock is usually acted upon successively by two punches while the section of stock is held in a die. In a given cycle the first punch will partially form the head of the rod stock and the second punch will finally form the stock. These punches are commonly referred to as a coning punch and a heading punch, respectively.

In one form of the invention the shifting of the punches and the locking thereof as they are brought into an operative position is achieved by a new improved punch shifting mechanism which not only quickly shifts the punch holders and punches thereon into an operative position for operating on a workpiece and locking the punches, but also gives a high degree of repeatability in the position of each punch.

An object of this invention is to provide a new and improved punch shifting mechanism for a heading machine.

Another object of this invention is to provide a new and improved punch-shifting and locking mechanism for a heading machine arranged to allow higher speeds of operation of the header.

Another object of this invention is to provide a new and improved punch-shifting mechanism for a two-blow header which also serves to lock the punches in a desired operative position with a high degree of repeatability.

A further object of this invention is to provide a new and improved toggle-type mechanism for shifting the punches of a double-blow heading machine which also serves to lock the punches in an operative position.

The features of the invention which are believed to be novel are set forth with particularity and distinctly claimed in the concluding portion of this specification.

However, the invention both as to its operation and organrzation, together with further objects and advantages thereof may best be appreciated by reference to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is a sectional view, in elevation, of a heading machine which may embody the invention;

FIG. 2 is a sectional view seen in the planes of line 22 of FIG. 1;

FIG. 3 is a sectional view seen in the plane of lines 33 of FIG. 2;

FIG. 4 is a view of linkage substantially as shown in FIG. 2, but in a different operative position from that shown in FIG. 2; and

FIG. 5 is a view similar to FIG. 4 but with some of the forward parts removed as seen in the plane of line 55 of FIG. 3.

In the drawings, and particularly with reference to FIG. 1 a heading machine is illustrated in part and comprises a frame 10 having a drive shaft 11 rotatably mounted therein. Drive shaft 11 has a crank 12 to which is rotatably mounted a pitman 13. Pitman 13 is connected to a pivot rod or pin 14 having also pivotally connected thereto a plunger 15 carried in a reciprocating gate 16 movable on frame 10. Gate 16 carries thereon punch holders 17 and 18 for heading and coning punches 19 and 20, respectively, which are arranged to sequentially 0perate upon a workpiece held in the cavity 21 of die 22. As drive shaft 11 rotates, crank 12 and pitman 13 reciprocate gate 16 on frame 10. Gate 16 includes an adjusting mechanism comprising a wedge 24 and block 25 relatively movable to each other by means of an adjustment screw 26. Plunger 15 may be connected to block 25, as by means of a pin 25a. This structure permits adjustment of the position of plunger 15 and, hence, pivot rod 14 to allow adjustment of pitman 13 with respect to gate 16.

An operatively positioned punch as represented by coning punch 20 is driven forward by a ram or plunger 27 carried in gate 16 upon a forming stroke of the machine. Gate 16 is reciprocated in frame 10, and punch holders 17 and 18 are alternately shifted into an operative or forming position in timed relation thereto as hereinafter described.

Each of punch holders 17 and 18 are mounted to a shifting arm or lever 30 and 31 as by means of bolts 32 and 33, respectively. The shifting arms 30 and 31 are non-rotatably mounted to or formed integral with pivot rods 35 and 36 which are pivotal in gate 16. Pivot rod 36 at the end opposite the shifting arm 31 has a portion thereof squared or provided with flats which receives thereon the complementary formed end of link 37 (FIG. 3). Pivot rods 35 and 36 are secured to the gate 16 as by means of nuts 38 and 39, respectively, received on threaded ends thereof together with spacing elements as may be required.

The punch holders 17 and 18 are thus pivotal with shifting arms 30 and 31 about the axis of pivot rods 35 and 36 carried in gate 16.

Mounted in gate 16 is a rod or pin 40. A member 41 is rotatable on pin 40 and, in turn, carries a pin 42 connected to a generally reciprocating shifting drive lever 43 which rocks member 41 about the axis of pin 40. The distance between the axis of pin 40 and pin 42 provides a link 44,

Member 41 includes integral or in fixed relation therewith a link 45 which pivotally connected to another link 46 by a pin 47 carried by member 41. Link 46 is connected as by pin 48 to shifting level 30 carrying punch holder 17 and punch 19 thereon. Drive lever 43 through pin 42 is pivotally connected to link 37 through a link 49. Link 37 is fast on pivot rod 36 and pivotally connected to link 49 by a pin 49a.

As may be seen in FIG. 2 heading punch 19 is in the heading position in front of ram 27. Shifting arm 30 when in the operative position engages a stop 50 carried on gate 16. Stop 50 is engaged, for example, by a positioning member 51 carried on arm 30 and having a flat 52 thereon which engages the stopping surface of stop 50.

As will hereinafter be made more apparent, links 45 and 46 are toggle links which act to very rapidly shift punch 19 to and from an operative position in front of ram 27. Similarly, links 44 and 49 are toggle links which act to shift punch 20 very rapidly when the toggle mechanisms are operated by drive lever 43. The provision -of these mechanisms, while permitting very rapid shifting, yields very positive positioning of the Punches as the punches decelerate to a soft stop at their operative positions.

To shift the heading punch 19 from the operative position before ram 27 as shown in FIG. 2, and shift coning punch 20 to such position, as shown in FIG. 1, drive lever 43 is moved to the left as viewed in FIG. 2. This produces clockwise motion of member 41 and links 44 and 45 in fixed relation therewith. This rotation of link 45 moves pin 47 clockwise and breaks the straight line connection of toggle link 45 to toggle link 46 and causes toggle link 46 to follow toggle link 45 in a non-linear path which is both rotational and translational. The totational part of such motion is about both pins 47 and 48, pin 47 being common with link 45. This movement of toggle link 45 is such as to cause shifting lever 30 to pivot about the axis of rod 35 and pivot arm 30 toward the position shown in FIG. 4.

This toggle type punch shifting mechanism produces a very high mechanical advantage so that a maximum holding force occurs when the punches are in an operative position before ram 27. It will be noted with reference to FIG. 2 that when the heading punch is in the position shown, the axes of rod 40 and pins 47 and 48 reside in a straight line, and any slight departure of the axis of pin 46 from that line would produce only small movement of the axis of pin 48 from such line, inasmuch as shifting lever 30 has only rotational movement about pivot rod 35. This relationship produces a desired deceleration of the punches as they approach an operative position during a shifting cycle. Accordingly, the positional r'epeatability of punch holder 17 and punch 19 therein is very high. Further, this straight line relationship of the axes predetermines a locking position of punch 19, and the toggle type linkage when in straight line relation, as in FIG. 2, locks punch 19 in a predetermined position in front of ram 27.

When the drive lever 43 is moved -to the left as viewed in FIG. 2 the punches shift so that the coning punch is operatively positioned in front of plunger 27 as illustrated in FIGS. 1 and 4.

When driver lever 43 is moved to the left, as viewed in FIG. 2, member 41 is pivoted about pin 40 in a clockwise direction which breaks the toggle links for heading punch 19 in a manner previously described, and at the same time pin 47 rotates about the axis of pin 40, as does the lower end of link 44 attached thereto. This also produces clockwise rotation of link 44 about pin 40. This motion moves link 49 toward the position shown in FIG. 4 and produces rotation of pivot rod 36 connected to link 49. As pivot rod 36 is rotated it pivots shift lever 31 about the axis of pivot rod 36 from the position shown in FIG. 2 to the position shown in FIG. 4. In this position coning punch 20 is operatively placed in front of plunger 27 to position the coning punch for a heading operation on the workpiece in die 22. In the operative position, punch holder or shift lever 31 engages a stop 53 carried on gate 16. Stop 53 is engaged by a positioning member 54 having a flat 55 thereon.

The position of the shifting mechanism and the punches carried thereby is now shown in FIG. 4 and it will be noted that the axes of pin 40, pin 42 and pin 49a reside '4 in a straight line. In this position the coning punch is locked in the coning position. Over-center travel of this toggle linkage is prevented by the abutment of stop 53 and member 54.

Reciprocation of drive lever 43 is achieved through a pair of cams 60 and 61 afiixed to a shaft 62 carried in frame 10. Shaft 62 is driven by main drive shaft 11 through a suitable connection such as bevel gears (not shown). Pivoted to frame 10 about a pin 63 is a lever 64 having a cam follower 65 pivoted thereto at 66. Also pivotally mounted about pin 63 is a second lever 67 having a cam follower 68 pivotally mounted thereto at 69. Lever 67 is pinned to lever 64 at 67a. Thus, as shaft 62 is rotated with cams 60 and 61 thereon cam 60 will act upon cam follower 65 to rotate lever 64 in a clockwise direction which moves drive lever 43 to the left as viewed in FIG. 2 to shift the heading punch 19 from an operative operation and shift coning punch 20 towards an operative position. Cam 61 acts upon cam follower 68 to rotate lever 64 in a counterclockwise direction and draw drive lever 43 to the right as viewed in FIG. 2 which acts to shift coning punch 20 from the position shown in FIG. 4 to that shown in FIG. 2, and simultaneously shift the heading punch from the position shown in FIG. 4 to that shown in FIG. 2. The ca-ms 60 and 61 are so selected that such shifting takes place upon rearward movement of gate 16 after a heading blow has been delivered and prior to the next advance of gate 16 due to rotation of shaft 11 with crank 12 thereon.

As shown in FIG. 2 the cams 60 and 61 are in a position where a heading blow has just been delivered by heading punch 19 and further rotation of cam 60 will bring a high area to bear against cam follower 65 and produce clockwise rotation of lever 64 which will break the toggle links 44 and 45 and shift heading punch 19 from the position shown in FIG. 2.

Rotation of the came 60 and 61 is in timed relation to rotation of shaft 11 and the timing of the earns 60 and 61 is so selected that shifting will commence after a heading blow has been delivered by gate 16, and gate 16 is retracted by crank 12. Thereafter, shifting of the punches will occur and the toggle linkages will lock the appropriate punch in place prior to delivery of the next heading blow by gate 16.

Carried 'by gate 16 are spring biased plungers 70 and 71 (more clearly shown in FIG. 5) which are contacted respectively by adjustable members in the form of set screws 72 and 73 carried in member 41. Each of plungers 70 and 71 is biased forward by a spring 74 and 75, respectively. The purpose of these plungers is to provide a cushioning force on the toggle linkages as they near a locking position. The energy then stored in the springs 74 and 75 aids in breaking the lock toggle linkage upon reciprocation of drive shaft 43.

It may thus be seen that the objects of the invention set forth above as well as those made apparent from the preceding description are efficiently attained. While a preferred embodiment has been set forth for purposes of disclosure, other embodiments of the invention as well as modifications to the disclosed embodiment thereof which do not depart from the scope of the invention may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments and modifications of the invention which do not depart from the spirit and scope of the invention.

What is claimed is:

1. In combination with a forming machine including a gate and a die, the gate being reciprocally movable toward and away from said die; first and second punch carriers pivotally carried on the gate, each of said carriers being pivotal between first and second positions, one of the positions of each carrier aligning said punch carriers with said die, and means for simultaneously pivoting said punch carriers in timed relation with movement of said gate to sequentially position said punch carriers in alignment with the die.

2. The invention of claim 1 further including a member pivotally carried by said gate, drive means for pivoting said member between first and second positions, and first and second linkage means connecting said member and said first and second punch carriers.

3. The invention of claim 2, wherein each of said linkage means is a two-bar toggle linkage which locks in place when the corresponding punch carrier and punch are aligned with the die.

4. The invention of claim 3 wherein one bar of each of said toggle linkages is formed integral with said member and said one bars are substantially oppositely disposed on either side of the pivotal axis of said member.

5. The invention of claim 2 further including limiting means carried by said gate for positioning each of said punch carriers when pivoted to a position of alignment with the die.

6. The invention of claim 3 wherein one of said toggle linkages comprises first and second pivotally connected links, said first link being pivotal with said member and said second link being pivotally connected to one of said punch carriers, the other of said toggle linkages comprising third and fourth pivotally connected links, said third link being pivotal with said member and said fourth link being pivotally connected to said other punch carrier, said first and third links being in fixed angular relation.

7. The invention of claim 6 wherein said first and third links are in fixed relationship with said member.

8. The invention of claim 6 wherein the pivotal axes of said first and second links and said third and fourth links reside in essentially straight lines when the associated punch carriers are positioned in alignment with the die.

9. The invention of claim 6 wherein the sum of the lengths of the first and second links are equal to the distance between the connection thereof to one of said punch carriers and the pivotal axis of said member when the punch carrier connected thereto is in an aligned posi' tion.

10. The invention of claim 6 wherein the sum of the lengths of the third and fourth links is greater than the distance between the pivotal connections thereof to the other of said punch carriers and the pivotal axis of said member.

11. In a heading machine having a die and a gate reciprocal towards and away from the die; first and second levers pivotally mounted on said gate, first and second punches, each of said punches being mounted to one of said levers, each of said levers adapted to be pivoted to a position where the punch thereon is in a predetermined position with respect. to said gate, a member pivotally mounted to the gate, said member including first and second links in fixed relation to each other extending from the pivotal axis of said member, third and fourth links each pivotally connecting one of said first and second links and to one of said first and second levers, said links being so arranged that upon pivotal movement of said member, one of said punchesis pivotally shifted towards said predetermined position and the other of said punches is pivotally shifted from said predetermined position, and means operated in timed relation to movement of the gate for pivoting said member to sequentially position said punches.

References Cited UNITED STATES PATENTS 2,659,906 11/1919 Watt 10-125 3,101,632 8/1963 Hoyt 10*125 3,260,096- 7/1966 Sakamura 10-12.5

CHARLES W. LANHAM, Primary Examiner B. J. MUSTAIKIS, Assistant Examiner US. Cl. X.R. 

